Petri Dishes
What are they and why do we use them? What types are there?
Petri dishes are tiny enclosures for the growing of microorganisms. They are used for containing solid agar medium in a sterile environment that can nonetheless be easily accessed for inoculation.
The two main types are;
Reusable, glass plates - require a lot of effort to wash, clean and autoclave between uses but are more environmentally friendly.
Single-use, plastic plates - Tend to come in pre-sterilised packs of 25. Much simpler to use but produce tons of plastic waste.
When do you use?
Anytime you wish to grow your organism on a solid medium. You can use agar slants as an alternative, which are generally made in a 5-15 ml bottles.
How do you use?
You can learn how to pour agar plates on the Plate Pouring page.
You can learn how to sterilely inoculate agar medium in a petri dish on the Sterile Technique page.